CVE-2025-8627
📋 TL;DR
The TP-Link KP303 Smartplug has an authentication bypass vulnerability that allows unauthenticated attackers to send protocol commands. This can cause unintended power-off conditions and potential information leaks. Only TP-Link KP303 (US) Smartplug devices running firmware versions before 1.1.0 are affected.
💻 Affected Systems
- TP-Link KP303 Smartplug (US)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could remotely control power states of connected devices, cause denial of service through repeated power cycling, and potentially extract sensitive information from the smartplug.
Likely Case
Remote attackers could turn off connected devices unexpectedly, disrupting operations and potentially causing data loss or equipment damage.
If Mitigated
With proper network segmentation and updated firmware, the risk is limited to internal network compromise scenarios.
🎯 Exploit Status
The vulnerability allows unauthenticated protocol commands, making exploitation straightforward for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.1.0
Vendor Advisory: https://www.tp-link.com/us/support/faq/4619/
Restart Required: Yes
Instructions:
1. Access the TP-Link Kasa app. 2. Navigate to the KP303 device settings. 3. Check for firmware updates. 4. If version 1.1.0 or later is available, install it. 5. The device will restart automatically after update.
🔧 Temporary Workarounds
Network Segmentation
allIsolate smartplug devices on a separate VLAN or network segment to limit attack surface.
Firewall Rules
allBlock external access to smartplug management ports and restrict internal access to authorized devices only.
🧯 If You Can't Patch
- Disconnect affected smartplugs from the network and use them as manual switches only.
- Replace affected devices with patched versions or alternative products.
🔍 How to Verify
Check if Vulnerable:
Check firmware version in TP-Link Kasa app: Device Settings > Firmware Version. If version is below 1.1.0, device is vulnerable.Check Version:
No CLI command available. Must use TP-Link Kasa mobile app or web interface.Verify Fix Applied:
After updating, verify firmware version shows 1.1.0 or higher in the Kasa app.📡 Detection & Monitoring
Log Indicators:
- Unexpected power state changes
- Unauthorized access attempts to smartplug management interface
Network Indicators:
- Unusual protocol traffic to smartplug devices on port 9999 (default Kasa port)
- External IP addresses attempting to communicate with smartplugs
SIEM Query:
source_ip != internal_range AND dest_port = 9999 AND protocol = TCP